Control device, control method, and electronic device

ABSTRACT

Provided is a control device that includes a calculation unit that calculates, on a basis of a result of capturing a subject image passed through a focus lens by using an imaging element including a plurality of phase difference detection regions, a focus position of each of the phase difference detection regions and a determination unit that determines a position of the focus lens on a basis of an average value of the focus positions of the phase difference detection regions calculated by the calculation unit and falling within a predetermined range from the focus position on an infinity side or macro side.

CROSS REFERENCE TO RELATED APPLICATIONS

The present application is a continuation application of U.S. patentapplication Ser. No. 15/745,563, filed on Jan. 17, 2018, which is a U.S.National Phase of International Patent Application No. PCT/JP2016/067290filed on Jun. 9, 2016, which claims priority benefit of Japanese PatentApplication No. JP 2015-151644 filed in the Japan Patent Office on Jul.31, 2015, the entire content of which is hereby incorporated byreference.

TECHNICAL FIELD

The present disclosure relates to a control device, a control method, acomputer program, and an electronic device.

BACKGROUND ART

With regard to an image capturing device, a method for realizingautofocus (AF) that performs focusing on a subject at a high speed byembedding pixels for detecting a phase difference in an imaging elementhas been widespread in recent years. Such AF is referred to as “AF basedon phase difference detection method”.

CITATION LIST Patent Literature Patent Literature 1

-   JP 2010-49209A

DISCLOSURE OF INVENTION Technical Problem

However, when a subject close to an image capturing device and a subjectfar from the image capturing device simultaneously exist in a region fordetecting a phase difference between subject images, neither of thesubjects can be in focus in principle in the AF based on the phasedifference detection method.

In view of this, the present disclosure proposes a control device, acontrol method, a computer program, and an electronic device, each ofwhich is new, is improved, and is capable of effectively determining alens position even in a case where a subject close to an image capturingdevice and a subject far from the image capturing device simultaneouslyexist in a region for detecting a phase difference between subjectimages.

Solution to Problem

According to the present disclosure, there is provided a control deviceincluding: a calculation unit configured to calculate, on a basis of aresult of capturing a subject image passed through a focus lens by usingan imaging element including a plurality of phase difference detectionregions, a focus position of each of the phase difference detectionregions; and a determination unit configured to determine a position ofthe focus lens on a basis of an average value of the focus positions ofthe phase difference detection regions calculated by the calculationunit and falling within a predetermined range from the focus position onan infinity side or macro side.

In addition, according to the present disclosure, there is provided acontrol device including: a calculation unit configured to calculate, ona basis of a result of capturing a subject image passed through a focuslens by using an imaging element including a plurality of phasedifference detection regions, a focus position of each of the phasedifference detection regions; and a determination unit configured todetermine a position of the focus lens on a basis of the focus positionon an infinity side or macro side if a number of the phase differencedetection regions whose focus positions are apart from the focusposition of the phase difference detection region serving as a referenceby a predetermined range or more, is a predetermined value or more.

In addition, according to the present disclosure, there is provided acontrol device including: a calculation unit configured to calculate, ona basis of a result of capturing a subject image passed through a focuslens by using an imaging element including a plurality of phasedifference detection regions, a focus position of each of the phasedifference detection regions and convert the focus positions into ahistogram; and a determination unit configured to determine a positionof the focus lens on a basis of the focus position on an infinity sideor macro side in a case where each of the focus positions of the phasedifference detection regions converted into the histogram satisfies afirst predetermined condition.

In addition, according to the present disclosure, there is provided acontrol method including: calculating, on a basis of a result ofcapturing a subject image passed through a focus lens by using animaging element including a plurality of phase difference detectionregions, a focus position of each of the phase difference detectionregions; and determining a position of the focus lens on a basis of anaverage value of the calculated focus positions of the phase differencedetection regions falling within a predetermined range from the focusposition on an infinity side or macro side.

In addition, according to the present disclosure, there is provided acontrol method including: calculating, on a basis of a result ofcapturing a subject image passed through a focus lens by using animaging element including a plurality of phase difference detectionregions, a focus position of each of the phase difference detectionregions; and determining a position of the focus lens on a basis of thefocus position on an infinity side or macro side if a number of thephase difference detection regions whose focus positions are apart fromthe focus position in the phase difference detection region serving as areference by a predetermined range or more, is a predetermined value ormore.

In addition, according to the present disclosure, there is provided acontrol method including: calculating, on a basis of a result ofcapturing a subject image passed through a focus lens by using animaging element including a plurality of phase difference detectionregions, a focus position of each of the phase difference detectionregions and converting the focus positions into a histogram; anddetermining a position of the focus lens on a basis of the focusposition on an infinity side or macro side in a case where each of thefocus positions of the phase difference detection regions converted intothe histogram satisfies a first predetermined condition.

In addition, according to the present disclosure, there is provided acomputer program for causing a computer execute calculating, on a basisof a result of capturing a subject image passed through a focus lens byusing an imaging element including a plurality of phase differencedetection regions, a focus position of each of the phase differencedetection regions, and determining a position of the focus lens on abasis of an average value of the calculated focus positions of the phasedifference detection regions falling within a predetermined range fromthe focus position on an infinity side or macro side.

In addition, according to the present disclosure, there is provided acomputer program for causing a computer execute calculating, on a basisof a result of capturing a subject image passed through a focus lens byusing an imaging element including a plurality of phase differencedetection regions, a focus position of each of the phase differencedetection regions, and determining a position of the focus lens on abasis of the focus position on an infinity side or macro side if anumber of the phase difference detection regions whose focus positionsare apart from the focus position in the phase difference detectionregion serving as a reference by a predetermined range or more, is apredetermined value or more.

In addition, according to the present disclosure, there is provided acomputer program for causing a computer execute calculating, on a basisof a result of capturing a subject image passed through a focus lens byusing an imaging element including a plurality of phase differencedetection regions, a focus position of each of the phase differencedetection regions and converting the focus positions into a histogram,and determining a position of the focus lens on a basis of the focusposition on an infinity side or macro side in a case where each of thefocus positions of the phase difference detection regions converted intothe histogram satisfies a first predetermined condition.

In addition, according to the present disclosure, there is provided anelectronic device including: an imaging optical system configured tocollect light; an imaging element configured to receive light from theimaging optical system and capture an image; and a signal processingunit configured to process a signal output by the imaging element. Thesignal processing unit includes a calculation unit configured tocalculate, on a basis of a result of capturing a subject image passedthrough a focus lens by using the imaging element including a pluralityof phase difference detection regions, a focus position of each of thephase difference detection regions, and a determination unit configuredto determine a position of the focus lens on a basis of an average valueof the focus positions of the phase difference detection regionscalculated by the calculation unit and falling within a predeterminedrange from the focus position on an infinity side or macro side.

Advantageous Effects of Invention

As described above, according to the present disclosure, it is possibleto provide a control device, a control method, a computer program, andan electronic device, each of which is new, is improved, and is capableof effectively determining a lens position even in a case where asubject close to an image capturing device and a subject far from theimage capturing device simultaneously exist in a region for detecting aphase difference between subject images.

Note that the effects described above are not necessarily limitative.With or in the place of the above effects, there may be achieved any oneof the effects described in this specification or other effects that maybe grasped from this specification.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a block diagram illustrating a configuration example of anembodiment of a camera module to which the present technology isapplied.

FIG. 2A is a plan view illustrating a configuration example of an imagesensor 13 seen from an imaging optical system 11A side.

FIG. 2B is a diagram illustrating a basic schematic configuration of asolid-state image capturing device including an image sensor 13according to the present technology.

FIGS. 3A and 3B are diagrams illustrating a configuration example ofnormal pixels 52.

FIGS. 4A, 4B, and 4C are diagrams illustrating a configuration exampleof detection pixels 53.

FIG. 5 is a diagram illustrating examples of sequences of pixel valuesof normal pixels 52, left light-shielding pixels 53L, and rightlight-shielding pixels 53R.

FIG. 6 is a diagram illustrating examples of a right light-shieldingsequence obtained from a line in which right light-shielding pixels 53Rexist and a left light-shielding sequence obtained from a line in whichleft light-shielding pixels 53L paired with the right light-shieldingpixels 53R exist.

FIG. 7 is a diagram for describing contrast detection AF (CDAF), phasedetection AF (PDAF), and hybrid AF.

FIGS. 8A and 8B are diagrams for describing a relationship between phasedifference and defocus amount.

FIG. 9 is an explanatory view illustrating an example of both far andclose subjects.

FIG. 10 is an explanatory view illustrating, by using a graph, anexample in which contrasts and phase differences of both far and closesubjects are obtained.

FIG. 11 is an explanatory view illustrating an example of a subjectdetection region.

FIG. 12 is an explanatory view illustrating a functional configurationexample of a main processing unit 14.

FIG. 13 is an explanatory view illustrating an outline of a method 1regarding lens position determination processing.

FIG. 14 is a flowchart showing lens position determination processingperformed by the main processing unit 14.

FIG. 15 is an explanatory view illustrating an outline of a method 2regarding lens position determination processing.

FIG. 16 is a flowchart showing lens position determination processingperformed by the main processing unit 14.

FIG. 17 is an explanatory view illustrating an outline of a method 3regarding lens position determination processing.

FIG. 18 is a flowchart showing lens position determination processingperformed by the main processing unit 14.

FIG. 19 is a flowchart showing lens position determination processingperformed by the main processing unit 14.

FIG. 20 is an explanatory view illustrating an outline of a method 5regarding lens position determination processing.

FIG. 21 is a flowchart showing lens position determination processingperformed by the main processing unit 14.

FIG. 22 is an explanatory view illustrating an outline of a method 6regarding lens position determination processing.

FIG. 23 is a flowchart showing lens position determination processingperformed by the main processing unit 14.

MODE(S) FOR CARRYING OUT THE INVENTION

Hereinafter, (a) preferred embodiment(s) of the present disclosure willbe described in detail with reference to the appended drawings. In thisspecification and the appended drawings, structural elements that havesubstantially the same function and structure are denoted with the samereference numerals, and repeated explanation of these structuralelements is omitted.

Note that description will be provided in the following order.1. Embodiment of present disclosure1.1. Configuration example1.2. Operation examples

2. Conclusion 1. Embodiment of Present Disclosure [1.1. ConfigurationExample of Camera Module]

First, a schematic configuration of a camera module according to anembodiment of the present disclosure will be described with reference toFIG. 1.

FIG. 1 is a block diagram illustrating a configuration example of anembodiment of a camera module to which the present technology isapplied.

In FIG. 1, a camera module includes a lens barrel 11, an optical filter12, an image sensor 13, a main processing unit 14, an illuminationcontrol unit 15, a sensor drive unit 16, a phase detection AF processingunit 17, an image processing unit 18, a focus drive unit 19, a displayunit 20, an operation unit 21, a flash memory 22, a focus actuator 23,and an illumination unit 24.

Note that, in FIG. 1, the camera module is integrally configured withthe lens barrel 11. However, the camera module can be configured so thatthe lens barrel 11 is removable.

The lens barrel 11 includes an imaging optical system 11A such as a lensgroup and a diaphragm and collects light incident thereon on the imagesensor 13 via the optical filter 12.

Note that a lens position (in other words, a focus position) of the lensgroup of the imaging optical system 11A is movable in an optical axis Ldirection. With this, it is possible to adjust a focus.

The optical filter 12 is an optical element for reducing false color andmoire generated in an image taken by the image sensor 13. That is, theoptical filter 12 is an optical low-pass filter, and a part ofcomponents of light from the imaging optical system 11A is attenuatedand is emitted toward the image sensor 13.

The image sensor 13 is an imaging element that takes an image byreceiving light (subject light) incident from the imaging optical system11A via the optical filter 12. It is possible to employ, for example, acomplementary metal oxide semiconductor (CMOS) image sensor as the imagesensor 13.

The image sensor 13 supplies (image signals of) the image taken bycapturing an image to the sensor drive unit 16.

The main processing unit 14 controls each block included in the cameramodule.

The main processing unit 14 includes a central processing unit (CPU) 31,a memory 32, an analog to digital converter (ADC) 33, a digital toanalog converter (DAC) 34, and a communication interface (I/F) 35.

The CPU 31 controls the illumination control unit 15, the flash memory22, or the like by executing programs stored on the memory 32, therebycausing various kinds of processing to be executed such as AF, taking animage, various kinds of image processing, and recording a taken image.

The memory 32 includes a volatile memory such as a random access memory(RAM), a nonvolatile memory such as an electrically erasableprogrammable read only memory (EEPROM), or the like and stores theprograms to be executed by the CPU 31 and data necessary to operate theCPU 31.

The data stored on the memory 32 is, for example, an AF parameter forphase detection AF described below.

The ADC 33 performs AD conversion from an analog signal into a digitalsignal. The DAC 34 performs DA conversion from a digital signal into ananalog signal. The communication I/F 35 controls communication with theInternet or the like.

The illumination control unit 15 performs control so that theillumination unit 24 emits light serving as light with which a subjectis illuminated and torch auxiliary light for AF.

That is, the illumination control unit 15 causes the illumination unit24 to emit (turn on) an electronic flash serving as light with which asubject is illuminated, in synchronization with image taking operationof the image sensor 13. Further, the illumination control unit 15 causesthe illumination unit 24 to emit torch auxiliary light insynchronization with AF operation.

The sensor drive unit 16 performs control so that the image sensor 13takes an image. Further, the sensor drive unit 16 performs AD conversionof image signals of the image taken by the image sensor 13 as necessaryand supplies the image signals to the main processing unit 14 and thephase detection AF processing unit 17.

The phase detection AF processing unit 17 calculates a lens movingamount for moving the lens position of (the lens group of) the imagingoptical system 11A by the phase detection AF by using pixel values ofdetection pixels described below among the image signals of the takenimage from the sensor drive unit 16 and supplies the lens moving amountto the main processing unit 14.

The image processing unit 18 performs image processing, such as yconversion, color interpolation, and compression/expansion using apredetermined compression/expansion method such as the jointphotographic experts group (JPEG), with respect to the image taken bythe image sensor 13 and supplied via the sensor drive unit 16 and themain processing unit 14. Further, the image processing unit 18calculates a contrast evaluation value indicating a contrast of thetaken image and supplies the contrast evaluation value to the mainprocessing unit 14. In the main processing unit 14, (control of)contrast detection AF is performed by using the contrast evaluationvalue from the image processing unit 18.

The focus drive unit 19 drives the focus actuator 23 in accordance withcontrol by the main processing unit 14 and moves the lens position ofthe imaging optical system 11A in the optical axis L direction, therebyadjusting a focus.

The display unit 20 includes, for example, a liquid crystal display(LCD) panel and displays information regarding an image-taking mode ofthe camera module, a preview image before taking an image, an image forchecking after taking an image, an image in a focused state at the timeof AF, and the like.

The operation unit 21 is a switch group to be operated by a user andincludes a power supply switch, a release (image-taking trigger) switch,a zoom operation switch, an image-taking mode selection switch, and thelike.

The flash memory 22 is detachable from the camera module. A taken imagesupplied from the main processing unit 14 is recorded (stored) on theflash memory 22.

The focus actuator 23 is driven by the focus drive unit 19 and moves thelens position of the imaging optical system 11A in the optical axis Ldirection.

The illumination unit 24 emits light serving as light with which asubject is illuminated and torch auxiliary light for AF in accordancewith control by the illumination control unit 15.

As the illumination unit 24, it is possible to employ, for example, aflash illumination device using a xenon tube, an LED illumination deviceincluding a light emitting diode (LED) capable of continuously emittinglight, or the like. In a case where the camera module is mounted on aportable device such as a smartphone, it is possible to employ acomparatively small LED illumination device as the illumination unit 24.

The illumination unit 24 emits light toward a field via a light emitterlens (not illustrated) in which a groove of a predetermined pattern isformed, thereby improving accuracy of AF with respect to a dark subjectand a low-contrast subject.

Note that the phase detection AF processing unit 17 can be included(provided) in the image sensor 13.

Further, the phase detection AF processing unit 17 can be realized byhardware or can also be realized by software. In a case where the phasedetection AF processing unit 17 is realized by software, for example,programs included in the software are installed in a computer such asthe main processing unit 14 and are executed by the CPU 31 of the mainprocessing unit 14.

In this case, processing that the CPU 31 performs in accordance with theprograms is not necessarily performed in time series in the order shownas flowcharts described below. That is, the processing that the CPU 31performs in accordance with the programs also includes processingexecuted in parallel or individually (for example, parallel processingor processing to be performed by object).

Herein, the programs can be recorded in advance on the memory 32 servingas a recording medium provided in the main processing unit 14 serving asa computer.

Alternatively, the programs can be stored (recorded) on, for example,the flash memory 22 that is a removable recording medium and be providedas so-called packaged software.

Note that the programs can be installed not only in the main processingunit 14 from the flash memory 22 but also in the memory 32 providedtherein by being downloaded into the main processing unit 14 via acommunication network such as the Internet or a broadcast network suchas terrestrial broadcasting.

Next, a configuration example of the image sensor 13 will be described.FIG. 2A is a plan view illustrating a configuration example of the imagesensor 13 seen from the imaging optical system 11A side.

The image sensor 13 has a light receiving surface 50 that receiveslight, and the light receiving surface 50 includes H×V number of pixels(H represents the number of pixels lined up in a horizontal row and Vrepresents the number of pixels lined up in a vertical column).

Herein, in the present embodiment, when the light receiving surface 50is divided into, for example, rectangular blocks each of which serves asa pixel group including a plurality of pixels, the block is alsoreferred to as “pixel block 51”.

FIG. 2A illustrates 9×9 pixels as a part of pixel groups included in thepixel block 51.

For example, (primary color) color filters of red (R), green (G), andblue (B) in a Bayer array are provided on the pixels in an on-chipmanner.

Herein, the pixels on which the color filters of R, G, and B areprovided are referred to as an R pixel, a G pixel, and a B pixel,respectively. The R pixel, the G pixel, and the B pixel have spectralsensitivities of R, G, and B light, respectively, because of the on-chipcolor filters. In the Bayer array, 2×2 pixels (2×2 means horizontalrow×vertical column) are considered to be a basic unit, and G pixels arearranged in diagonal positions and an R pixel and a B pixel are arrangedin the remaining two positions.

In FIG. 2A, in 2×2 pixels considered to be a basic unit, for example,the R pixel is arranged in an upper right position, the B pixel isarranged in a lower left position, and the G pixels are arranged in anupper left position and a lower right position.

In the Bayer array, the above basic unit is repeatedly arrangedhorizontally and vertically.

Note that, in FIG. 2A, the G pixel in the upper left position of thebasic unit is denoted by Gr, and the G pixel in the lower right positionthereof is denoted by Gb.

The light receiving surface 50 includes detection pixels 53 fordetecting a phase difference to be used for the phase detection AF andnormal pixels (pixels used for the purpose of obtaining an image toserve as a taken image) 52 that are other than the detection pixels 53and are not used to detect a phase difference.

Although details of the detection pixels 53 will be described below,left half portions or right half portions of the detection pixels 53 areshielded in order to receive, for example, light passed through a righthalf portion or left half portion serving as different regions of anexit pupil of the imaging optical system 11A.

Note that, regarding a taken image, a main component of luminance isacquired on the basis of pixel values of the G pixels.

Next, a basic schematic configuration of a solid-state image capturingdevice including the image sensor 13 according to the present technologywill be described with reference to FIG. 2B.

As a first example, a solid-state image capturing device 330 illustratedin an upper part of FIG. 2B includes a pixel region 332, a controlcircuit 333, and a logic circuit 334 including the sensor drive unit 16,phase detection AF processing unit 17, and the like on a singlesemiconductor chip 331.

As a second example, a solid-state image capturing device 340illustrated in a middle part of FIG. 2B includes a first semiconductorchip unit 341 and a second semiconductor chip unit 342. A pixel region343 and a control circuit 344 are mounted on the first semiconductorchip unit 341, and a logic circuit 345 including the above-describedsensor drive unit 16, phase detection AF processing unit 17, and thelike is mounted on the second semiconductor chip unit 342. Then, thesolid-state image capturing device 340 serving as a single semiconductorchip is configured by electrically connecting the first semiconductorchip unit 341 and the second semiconductor chip unit 342 with eachother.

As a third example, a solid-state image capturing device 350 illustratedin a lower part of FIG. 2B includes a first semiconductor chip unit 351and a second semiconductor chip unit 352. A pixel region 353 is mountedon the first semiconductor chip unit 351, and a control circuit 354 anda logic circuit 355 including the above-described sensor drive unit 16,phase detection AF processing unit 17, and the like are mounted on thesecond semiconductor chip unit 352. Then, the solid-state imagecapturing device 350 serving as a single semiconductor chip isconfigured by electrically connecting the first semiconductor chip unit351 and the second semiconductor chip unit 352 with each other.

Next, a configuration example of pixels will be described. FIGS. 3A and3B are diagrams illustrating a configuration example of the normalpixels 52.

FIG. 3A is a plan view illustrating a configuration example of a regiononly including the normal pixels 52 in the light receiving surface 50.

FIG. 3B is a cross-sectional view schematically illustrating across-section of the normal pixel 52 taken along a line segment L11 ofFIG. 3A.

The normal pixel 52 is configured so that a photo diode (PD) 61, acontact layer (CL) 62, a color filter 63, and an on-chip lens(microlens) 64 are laminated from the bottom in FIGS. 3A and 3B.

In the normal pixel 52, among light incident on the on-chip lens 64,light having a predetermined color component passes through the colorfilter 63 and is incident on the PD 61 via the transparent CL 42. In thePD 61, incident light is received and is subjected to photoelectricconversion. An electric signal obtained as a result of the photoelectricconversion in the PD 61 is output as a pixel value of the normal pixel52.

FIGS. 4A, 4B, and 4C are diagrams illustrating a configuration exampleof the detection pixels 53.

FIG. 4A is a plan view illustrating a configuration example of a regionincluding the detection pixels 53 in the light receiving surface 50.

In FIGS. 4A, 4B, and 4C, among R pixels, G pixels, and B pixels of thelight receiving surface 50, some G pixels serve as the detection pixels53. Note that, instead of the G pixels, some R pixels or some B pixelscan be employed as the detection pixels.

The detection pixels 53 includes left light-shielding pixels 53L whoseleft half portion shields light and right light-shielding pixels 53Rwhose right half portion shields light in order to, for example, receivelight passed through the right half portion or left half portion servingas the different regions of the exit pupil of the imaging optical system11A.

In order to detect a phase difference between two images obtained bysplitting the exit pupil of the imaging optical system 11A, the leftlight-shielding pixel 53L and the right light-shielding pixel 53R arepaired.

FIG. 4B is a cross-sectional view schematically illustrating across-section of the left light-shielding pixel 53L among the detectionpixels 53 taken along a line segment L21 of FIG. 4A.

FIG. 4C is a cross-sectional view schematically illustrating across-section of the right light-shielding pixel 53R among the detectionpixels 53 taken along a line segment L22 of FIG. 4A.

Note that structural elements in the detection pixel 53 in FIGS. 4A, 4B,and 4C, which are configured in the same way as the normal pixel 52 inFIGS. 3A and 3B, are denoted by the reference signs same as thestructural elements in the normal pixel 52, and, hereinafter,description thereof will be omitted as appropriate.

The detection pixel 53 is similar to the normal pixel 52 in that the PD61 to the on-chip lens 64 are included. However, the detection pixel 53is different from the detection pixel 53 in that a light-shielding film66 is provided in the CL 62.

In the left light-shielding pixel 53L among the detection pixels 53, asillustrated in FIG. 4B, the light-shielding film 66 is provided toshield light incident on the left half portion of the leftlight-shielding pixel 53L. With this, in the left light-shielding pixel53L, only the right half portion from the center of the on-chip lens 64,which is seen from the on-chip lens 64 side, is opened. As a result, forexample, light passed through the right half portion of the exit pupilof the imaging optical system 11A is received by the leftlight-shielding pixel 53L.

In the right light-shielding pixel 53R among the detection pixels 53, asillustrated in FIG. 4C, the light-shielding film 66 is provided toshield light incident on the right half portion of the rightlight-shielding pixel 53R. With this, in the right light-shielding pixel53R, only the left half portion from the center of the on-chip lens 64,which is seen from the on-chip lens 64 side, is opened. As a result, forexample, light passed through the left half portion of the exit pupil ofthe imaging optical system 11A is received by the right light-shieldingpixel 53R.

Pupil split of the exit pupil of the imaging optical system 11A in ahorizontal direction (lateral direction) is performed by the abovedescribed pair of the left light-shielding pixel 53L and the rightlight-shielding pixel 53R.

Note that the detection pixels 53 are regularly arranged over the wholelight receiving surface 50 in, for example, the horizontal direction. Ifthe number of detection pixels 53 is increased, a phase difference, morespecifically, accuracy of the phase detection AF, is improved. However,an image quality of a taken image is deteriorated. Therefore, it ispossible to determine the number of detection pixels 53 and arrangementpositions thereof in consideration of a trade-off between accuracy ofthe phase detection AF and an image quality of a taken image.

Further, an arrangement pattern of the detection pixels 53 can be fixedor can be different depending on, for example, a position such as acenter portion or a peripheral portion of the light receiving surface50.

FIG. 5 is a diagram illustrating examples of sequences of pixel valuesof the normal pixels 52, the left light-shielding pixels 53L, and theright light-shielding pixels 53R.

Herein, a sequence of pixel values of the normal pixels 52 arranged in aline (horizontal line) is also referred to as “normal sequence”.Further, a sequence of pixel values of the left light-shielding pixels53L arranged in a line is also referred to as “left light-shieldingsequence”, and a sequence of pixel values of the right light-shieldingpixels 53R in a line is also referred to as “right light-shieldingsequence”.

FIG. 5 illustrates a normal sequence and a right light-shieldingsequence obtained from a line in which the normal pixels 52 and theright light-shielding pixels 53R coexist, and a left light-shieldingsequence obtained from a line in which the left light-shielding pixels53L paired with the right light-shielding pixels 53R exist.

In FIG. 5, a horizontal axis shows a position of a pixel and a verticalaxis shows a pixel value (brightness).

A subject image appearing as the normal sequence is separated by thedetection pixels 53 (left light-shielding pixels 53L and rightlight-shielding pixels 53R) into an image appearing as the leftlight-shielding sequence (hereinafter, also referred to as “leftlight-shielding image”) and an image appearing as the rightlight-shielding sequence (hereinafter, also referred to as “rightlight-shielding image”).

When detecting a phase difference showing a relative positionalrelationship between left light-shielding image and rightlight-shielding image by, for example, performing correlation operationof the left light-shielding image and the right light-shielding image,it is possible to detect, on the basis of the phase difference, adefocus amount that is a shift amount of a focus of the subject image.

FIG. 6 is a diagram illustrating examples of the right light-shieldingsequence obtained from the line in which the right light-shieldingpixels 53R exist and the left light-shielding sequence obtained from theline in which the left light-shielding pixels 53L paired with the rightlight-shielding pixels 53R exist.

In FIG. 6, a horizontal axis shows a position of a pixel and a verticalaxis shows a pixel value.

In FIG. 6, some G pixels in a line L31 in which R pixels that are thenormal pixels 52 exist serve as the right light-shielding pixels 53R.Further, in FIG. 6, some G pixels in a line L32 immediately after theline L31 serve as the left light-shielding pixels 53L. In addition, forexample, the right light-shielding pixels 53R and the leftlight-shielding pixels 53L that are in lower-left oblique portions fromthe right light-shielding pixels 53R are paired to detect a phasedifference (between a left light-shielding image and a rightlight-shielding image).

By using the left light-shielding sequence and the right light-shieldingsequence, the phase difference can be obtained (detected) in the unit ofthe number of pixels.

A defocus amount obtained when a subject image is in a focused state is0, and therefore it is possible to perform AF by moving the lensposition of the imaging optical system 11A so that a defocus amountdetected on the basis of the phase difference is 0.

Next, autofocus (AF) will be described. FIG. 7 is a diagram fordescribing the contrast detection AF (CDAF), the phase detection AF(PDAF), and hybrid AF.

In FIG. 7, a horizontal axis shows the lens position of the imagingoptical system 11A and a vertical axis shows a contrast evaluation valueand a phase difference.

Further, in FIG. 7, a left direction of the horizontal axis shows aninfinity (Inf) direction and a right direction shows a macro direction.

Herein, the Inf direction is a direction in which a subject at a farposition is in focus, and the macro direction is a direction in which asubject at a close position is in focus.

In the contrast detection AF (CDAF), the contrast evaluation valueindicating a contrast of an image to be taken is obtained at each lensposition while moving the lens position. The lens position is moved sothat the contrast evaluation value is increased.

The contrast evaluation value becomes the largest at a focusingposition, and therefore, in the contrast detection AF, the lens positionis moved to be close to the focusing position and passes the focusingposition once. Thereafter, the lens position is slightly moved to passthe focusing position again, and, by using contrast evaluation valuesobtained at that time, a lens position at which the largest contrastevaluation value is obtained, i.e., the focusing position is detected.Then, the lens position is moved to the focusing position that is aposition at which the largest contrast evaluation value is obtained.

In the phase detection AF (PDAF), it is assumed that the phasedifference is 0 when the lens position is the focusing position, thelens position is, so to speak, directly moved so that the phasedifference becomes 0.

In the hybrid AF, the lens position is first moved to a position nearthe focusing position by the phase detection AF, and thereafter the lensposition is moved to the focusing position with high accuracy by thecontrast detection AF.

Next, phase difference and a defocus amount will be described. FIGS. 8Aand 8B are diagrams for describing a relationship between phasedifference and defocus amount.

Both the phase difference and the defocus amount indicate a shift amountof a focus of a subject image. However, in AF, the defocus amount isused as a physical amount showing how far it is from a current lensposition to the focusing position.

That is, in AF, the defocus amount shows a distance and direction fromthe current lens position to the focusing position.

FIG. 8A is a diagram for describing the defocus amount.

When a lens position at which the largest contrast evaluation value isobtained is used as the focusing position, the defocus amount shows adistance and direction from the current lens position to the focusingposition.

Herein, when a moving amount of the lens position is shown by the um(micrometer), it is possible to employ um as a unit of the defocusamount.

Meanwhile, the phase difference shows a shift amount of a focus of asubject image as a relative positional relationship between leftlight-shielding image and right light-shielding image, and a unitthereof is the number of pixels.

FIG. 8B is a diagram illustrating a relationship between phasedifference and defocus amount.

In FIG. 8B, a horizontal axis shows a phase difference and a verticalaxis shows a defocus amount.

The phase difference and the defocus amount ideally have a linearrelationship as illustrated in FIG. 8B, and therefore it is possible toobtain one of the phase difference and the defocus amount on the basisof the other one of the phase difference and the defocus amount.

Herein, when a coefficient for changing (converting) a phase differenceinto a defocus amount is used as a conversion factor a, it is possibleto obtain a defocus amount by using a phase difference in accordancewith Expression (1).

Defocus amount [um]=Phase difference [number of pixels]×Conversionfactor a [um/number of pixels]  (1)

When the relationship between phase difference and defocus amount isused as a conversion characteristic, the conversion characteristic isideally indicated by a straight line. As illustrated in FIG. 8B, in atwo-dimensional plane in which a horizontal axis shows a phasedifference and a vertical axis shows a defocus amount, the conversionfactor a indicates slope of the conversion characteristic indicated bythe straight line.

The conversion factor a can be acquired in advance (before shipment) byimplementing a test and the like of the camera module in a factory thatmanufactures the camera module.

Next, there will be described focusing processing performed when, in acase where focusing is performed on a subject by using the phasedetection AF (PDAF), both far and close subjects are included in asubject detection region for detecting a subject.

FIG. 9 is an explanatory view illustrating an example in which subjectsexist at both far and close positions. FIG. 9 illustrates an example inwhich a fence 121 and an automobile 122 exist as subjects in a frontside and in a back side, respectively.

In a case where subjects exist at both far and close positions asdescribed above and focusing is attempted with respect to the subjectsby using the phase detection AF (PDAF), neither of the subjects can bein focus in some cases.

FIG. 10 is an explanatory view illustrating, by using a graph, anexample in which contrasts and phase differences of both the far andclose subjects illustrated in FIG. 9 are obtained. A horizontal axis inthe graph of FIG. 10 shows the lens position of the imaging opticalsystem 11A, and a vertical axes therein show a contrast (left side) anda phase difference (right side).

In the phase detection AF (PDAF), the lens position is controlled to bemoved so that the phase difference becomes 0. Meanwhile, in the contrastdetection AF (CDAF), the lens position is controlled to be moved to apeak of the contrast.

In the graph illustrated in FIG. 10, p2 indicates a lens position atwhich the phase difference is 0, p1 indicates a lens position at which acontrast of the subject on the far side reaches a peak, and p3 indicatesa lens position at which a contrast of the subject on the close sidereaches a peak.

However, as illustrated in FIG. 10, when a phase difference is obtainedin a situation in which both far and close subjects exist, the lensposition at which the phase difference is 0 is different from both thelens position at which the contrast of the subject on the far sidereaches a peak and the lens position at which the contrast of thesubject on the close side reaches a peak. Therefore, in a case wheresubjects exist at both far and close positions and focusing is attemptedwith respect to the subjects by using the phase detection AF (PDAF),neither of the subjects can be in focus in some cases.

In view of this, the disclosers of the present technology havediligently studied a technology of efficiently determining a lensposition even in a case where both far and close subjects exist.

As a result, the disclosers of the present technology have devised atechnology that divides a region for detecting a subject in a capturedimage (subject detection region) and obtains values of defocus amounts(defocus values) of the subject detection region and each dividedregion, thereby efficiently determining a lens position by using thosedefocus values even in a case where both far and close subjects exist.

FIG. 11 is an explanatory view illustrating an example of the subjectdetection region. FIG. 11 illustrates an example in which a subjectdetection region 130 is divided into nine regions in total, i.e., threeregions in a vertical column and three regions in a horizontal row. Notethat division of the subject detection region 130 is not limited to suchan example.

Further, FIG. 11 illustrates a diagram in which all the divided regionsare included in the subject detection region 130. However, the presentdisclosure is not limited to such an example. That is, a plurality ofsubject detection regions, each of which has at least a part overlappingwith the subject detection region 130 and is smaller than the subjectdetection region 130, may be prepared and a defocus value of each regionmay be obtained.

In the present embodiment, defocus values of the subject detectionregion 130 and the nine divided regions are calculated in a state inwhich the lens position of the imaging optical system 11A is at apredetermined position, and the lens position of the imaging opticalsystem 11A is determined by using those defocus values. Hereinafter,processing for determining the lens position of the imaging opticalsystem 11A will also be simply referred to as “lens positiondetermination processing”.

FIG. 12 is an explanatory view illustrating a functional configurationexample of the main processing unit 14. As illustrated in FIG. 12, themain processing unit 14 includes a calculation unit 111 and adetermination unit 112.

The calculation unit 111 calculates defocus values of the subjectdetection region 130 and the nine divided regions in a state in whichthe lens position of the imaging optical system 11A is at apredetermined position. When the defocus values are added to the lensposition obtained when the defocus values are calculated, the lensposition corresponds to a lens position at which a target subject is infocus. The defocus values calculated by the calculation unit 111 areused for the lens position determination processing performed by thedetermination unit 112.

When the calculation unit 111 calculates the defocus value of eachregion, the calculation unit 111 may convert the calculated defocusvalues into a histogram. The defocus values converted into a histogramby the calculation unit 111 are used for the lens position determinationprocessing performed by the determination unit 112.

Further, the calculation unit 111 may smooth the defocus valuesconverted into the histogram. The defocus values converted into thehistogram and smoothed by the calculation unit 111 are used for the lensposition determination processing performed by the determination unit112.

The determination unit 112 performs the lens position determinationprocessing in the subject detection region 130 by using the defocusvalues calculated by the calculation unit 111. Details of the lensposition processing of the imaging optical system 11A performed by thedetermination unit 112 will be described below.

Hereinabove, a functional configuration example of the main processingunit 14 has been described. Next, operation of the camera module, inparticular, the lens position determination processing performed by themain processing unit 14 will be described.

[1.2. Operation Examples]

(Method 1)

A method 1 regarding the lens position determination processing is amethod of arranging the calculated defocus values of the subjectdetection region 130 and the nine divided regions and determining that asubject exists on the macro side or infinity side if the number ofregions between a macro-side or infinity-side defocus value and apredetermined threshold is a predetermined value or more, therebydetermining the lens position of the imaging optical system 11A.

FIG. 13 is an explanatory view illustrating an outline of the method 1regarding the lens position determination processing. FIG. 13illustrates an example in which the calculated defocus values of thesubject detection region 130 and the nine divided regions are arranged.In the method 1, the processing is started from the macro-side orinfinity-side defocus value, and the number of regions between thedefocus value and the predetermined threshold is compared with thepredetermined value.

Note that a reference frame indicates the whole subject detection region130. In the following description, the whole subject detection region130 will also be referred to as “reference frame”, and each frame intowhich the reference frame is divided will also be referred to as“divided frame”.

Then, if, as a result of the comparison, the number of regions is thepredetermined value or more, it is determined that a subject exists onthe macro side or infinity side, the defocus values of the regions areaveraged, and the lens position of the imaging optical system 11A isdetermined by using the average value. Then, the imaging optical system11A is moved to the determined position, and PDAF is executed.

FIG. 14 is a flowchart showing the lens position determinationprocessing performed by the main processing unit 14 by using themethod 1. Hereinafter, the lens position determination processingperformed by the main processing unit 14 by using the method 1 will bedescribed with reference to FIG. 14.

The main processing unit 14 first calculates defocus values of thereference frame and divided frames in a state in which the lens positionof the imaging optical system 11A is at a predetermined position (StepS101). The calculation of defocus values in Step S101 is performed bythe calculation unit 111.

The main processing unit 14 may be configured not to use, in thesubsequent lens position determination processing, a frame whose phasedifference reliability does not satisfy a predetermined reference whenthe defocus values of the reference frame and divided frames arecalculated. The phase difference reliability is disclosed in JP2010-139942A previously proposed by the applicant of the presentapplication.

When the defocus values of the reference frame and divided frames arecalculated in Step S101, then the main processing unit 14 acquires thenumber of frames between a defocus value closest to the end of the Infside or the end of the Macro side and a predetermined threshold (StepS102). The acquisition processing in Step S102 is performed by, forexample, the determination unit 112.

Note that the main processing unit 14 may exclude the reference framewhen acquiring the number of frames. The main processing unit 14 maydetermine from which side to acquire the number of frames, the Inf sideor the Macro side, on the basis of a previous setting or on the basis ofdesignation made by a user.

When the number of frames is acquired in Step S102, then the mainprocessing unit 14 determines whether or not the acquired number offrames is a predetermined value or more (Step S103). The determinationprocessing in Step S103 is performed by, for example, the determinationunit 112.

If, as a result of the determination in Step S103, the number of framesis the predetermined value or more (Step S103, Yes), the main processingunit 14 determines that a subject exists on the infinity side or macroside in the reference frame, determines the lens position of the imagingoptical system 11A on the basis of an average of defocus values of theframes falling within the threshold, and causes the phase detection AFprocessing unit 17 to execute PDAF (Step S104). The determination of thelens position of the imaging optical system 11A is performed by thedetermination unit 112.

On the contrary, if, as a result of the determination in Step S103, thenumber of frames is less than the predetermined value (Step S103, No),the main processing unit 14 determines whether or not all the frames hasbeen searched (Step S104). The determination processing in Step S104 isperformed by, for example, the determination unit 112.

In a case where, as a result of the determination in Step S104, all theframes has been searched (Step S104, Yes), the main processing unit 14determines the lens position of the imaging optical system 11A on thebasis of the defocus amount of the reference frame and causes PDAF orCDAF to be executed (Step S105). The determination of the lens positionof the imaging optical system 11A is performed by the determination unit112.

On the contrary, in a case where, as a result of the determination inStep S104, not all the frames have been searched (Step S104, No), themain processing unit 14 excludes a frame closest to the Inf side or theend of the Macro side (Step S106). The exclusion processing in Step S106is performed by, for example, the determination unit 112.

Then, when the frame closest to the end of Inf side or the end of theMacro side is excluded in Step S106, the main processing unit 14 returnsto the processing in Step S102 and acquires the number of frames betweena defocus value (after exclusion) closest to the end of the Inf side orthe end of the Macro side and the predetermined threshold.

By executing the above-described series of operation, even if subjectsexist on both the infinity side (Inf side) and the macro side (Macroside) in the subject detection region 130, the main processing unit 14can determine the lens position of the imaging optical system 11A sothat one of the subjects can be in focus.

(Method 2)

A method 2 regarding the lens position determination processing is amethod of arranging the calculated defocus values of the subjectdetection region 130 and the nine divided regions, determining whetheror not the number of regions that is out of the ranges from the defocusvalue of the reference frame to predetermined thresholds ininfinity-side (Inf-side) and macro-side (Macro-side) directions is apredetermined value or more, and determining that a subject exists onthe macro side or infinity side in a case where the number of regionsthat is out of the range between the predetermined thresholds is thepredetermined value or more, thereby determining that the lens positionof the imaging optical system 11A is on the macro side or infinity side.

FIG. 15 is an explanatory view illustrating an outline of the method 2regarding the lens position determination processing. FIG. 15illustrates an example in which the calculated defocus values of thesubject detection region 130 and the nine divided regions are arranged.

In the method 2, it is determined whether or not the number of regionsthat is out of the ranges from the defocus value of the reference frameto the predetermined thresholds in the infinity-side (Inf-side) andmacro-side (Macro-side) directions is the predetermined value or more.

If the number of regions that is out of the ranges between thepredetermined thresholds is the predetermined value or more, it isdetermined that a subject exists on the macro side or infinity side, andthe lens position of the imaging optical system 11A is to be on themacro side or infinity side.

FIG. 16 is a flowchart showing the lens position determinationprocessing performed by the main processing unit 14 by using the method2. Hereinafter, the lens position determination processing performed bythe main processing unit 14 by using the method 2 will be described withreference to FIG. 16.

The main processing unit 14 first calculates defocus values of thereference frame and divided frames in a state in which the lens positionof the imaging optical system 11A is at a predetermined position (StepS111). The calculation of defocus values in Step S111 is performed bythe calculation unit 111.

In a way similar to the method 1, the main processing unit 14 may beconfigured not to use, in the subsequent lens position determinationprocessing, a frame whose phase difference reliability does not satisfya predetermined reference when the defocus values of the reference frameand the divided frames are calculated.

When the defocus values of the reference frame and the divided framesare calculated in Step S111, then the main processing unit 14 acquiresthe number of frames that are out of a ranges from the defocus value ofthe reference frame to predetermined thresholds (Step S112). Theacquisition processing in Step S112 is performed by, for example, thedetermination unit 112.

When the number of frames that are out of the ranges from the defocusvalue of the reference frame to the predetermined thresholds is acquiredin Step S112, then the main processing unit 14 determines whether or notthe acquired number of frames is a predetermined value or more (StepS113). The determination processing in Step S113 is performed by, forexample, the determination unit 112.

If, as a result of the determination in Step S113, the number of framesis the predetermined value or more (Step S113, Yes), the main processingunit 14 determines the lens position on the basis of defocus values onthe Inf-side or Macro-side and causes PDAF or CDAF to be executed (StepS114). The determination of the lens position of the imaging opticalsystem 11A is performed by the determination unit 112.

For example, if the number of frames that are out of the ranges from thedefocus value of the reference frame to the predetermined thresholds aretwo on the Inf side and four on the Macro side and the predeterminedvalue is five, the main processing unit 14 determines the lens positionon the basis of defocus values on the Inf side or the Macro side andcauses PDAF or CDAF to be executed.

The main processing unit 14 may determine which of PDAF or CDAF to beexecuted, on the basis of a previous setting or on the basis ofdesignation made by a user.

Further, when causing PDAF or CDAF to be executed, the main processingunit 14 may determine which of the defocus values on the Inf side or thedefocus values on the Macro side to use, on the basis of a previoussetting or on the basis of designation made by a user.

Further, regarding determination on which of the defocus values on theInf side or the defocus values on the Macro side to use when causingPDAF or CDAF to be executed, the main processing unit 14 may determineto use the defocus values on one of the sides including the largernumber of frames between the predetermined threshold and a defocus valueclosest to the end of the Inf side or the end of the Macro side.

Further, when selecting a frame on the Inf side or the Macro side frame,the main processing unit 14 may select a frame farthest from thereference frame or may select a frame closest to the reference frame.Further, the main processing unit 14 may determine the lens position onthe basis of an average of the defocus values of frames on the Inf sideor frames on the Macro side.

On the contrary, if, as a result of the determination in Step S113, thenumber of frames is less than the predetermined value (Step S113, No),the main processing unit 14 determines the lens position on the basis ofthe defocus value of the reference frame and causes PDAF or CDAF to beexecuted (Step S115). The determination of the lens position of theimaging optical system 11A is performed by the determination unit 112.

By executing the above-described series of operation, even if subjectsexist on both the infinity side (Inf side) and the macro side (Macroside) in the subject detection region 130, the main processing unit 14can determine the lens position of the imaging optical system 11A sothat one of the subjects can be in focus.

Further, the main processing unit 14 can change an adjustment width inthe lens position determination processing by using the predeterminedthreshold used in the frame acquisition processing in Step S112 or thepredetermined value used in the determination processing in Step S113.

(Method 3)

A method 3 regarding the lens position determination processing is amethod of converting the calculated defocus values of the subjectdetection region 130 and the nine divided regions into a histogram anddetermining that a subject exists on the macro side or infinity side ifthe defocus values converted into the histogram satisfy a predeterminedcondition, thereby determining whether the lens position of the imagingoptical system 11A is to be on the macro side or infinity side.

FIG. 17 is an explanatory view illustrating an outline of the method 3regarding the lens position determination processing. FIG. 17illustrates an example in which the calculated defocus values of thesubject detection region 130 and the nine divided regions are arrangedin a histogram.

In this method 3 as the predetermined condition, a condition that, in acase where unit elements included in the histogram (“unit element” meansa single square in the histogram of FIG. 17) are adjacent, the number ofunit elements is counted and the number of groups (bins) in which thenumber of unit elements is a threshold or more is two or more is used.If this condition is satisfied, it is determined that a subject existson the macro side or infinity side, and the lens position of the imagingoptical system 11A is determined to be on the macro side or infinityside.

In the example of FIG. 17, the number of adjacent unit elements is 3, 3,1, 2, and 1 from the left side. When the threshold is two, the number ofgroups (bins) equal to or more than the threshold is three. Therefore,because the number of groups (bins) equal to or more than the thresholdis two or more, it is determined that a subject exists on the macro sideor infinity side, and the lens position of the imaging optical system11A is determined to be on the macro side or infinity side.

FIG. 18 is a flowchart showing the lens position determinationprocessing performed by the main processing unit 14 by using the method3. Hereinafter, the lens position determination processing performed bythe main processing unit 14 by using the method 3 will be described withreference to FIG. 18.

The main processing unit 14 first calculates defocus values of thereference frame and divided frames in a state in which the lens positionof the imaging optical system 11A is at a predetermined position andconverts the defocus values into a histogram (Step S121). Thecalculation of defocus values and the conversion thereof into ahistogram in Step S121 are performed by the calculation unit 111.

In a way similar to the methods 1 and 2, the main processing unit 14 maybe configured not to use, in the subsequent lens position determinationprocessing, a frame whose phase difference reliability does not satisfya predetermined reference when the defocus values of the reference frameand divided frames are calculated.

When the defocus values of the reference frame and divided frames arecalculated and are converted into a histogram in Step S121, then themain processing unit 14 acquires the number of bins including adjacentunit elements in the histogram (Step S122). The acquisition processingin Step S122 is performed by, for example, the determination unit 112.

When the number of bins including adjacent unit elements in thehistogram is acquired in Step S112, then the main processing unit 14determines whether or not the number of bins in which the number of unitelements is a predetermined threshold or more is two or more (StepS123). The determination processing in Step S123 is performed by, forexample, the determination unit 112. Note that the number of bins usedas a reference of the determination is not limited to two or more, andthe number of bins used as a reference may be “three or more”, or thelike.

If, as a result of the determination performed in Step S123, the numberof bins in which the number of unit elements is the predeterminedthreshold or more is two or more (Step S123, Yes), the main processingunit 14 determines the lens position on the basis of defocus values onthe Inf side or the Macro side and causes PDAF or CDAF to be executed(Step S124). The determination of the lens position of the imagingoptical system 11A is performed by the determination unit 112.

The main processing unit 14 may determine which of PDAF or CDAF to beexecuted, on the basis of a previous setting or on the basis ofdesignation made by a user.

Further, when causing PDAF or CDAF to be executed, the main processingunit 14 may determine which of the defocus values on the Inf side or thedefocus values on the Macro side to use, on the basis of a previoussetting or on the basis of designation made by a user.

Further, regarding determination on which of the defocus values on theInf side or the defocus values on the Macro side to use when causingPDAF or CDAF to be executed, the main processing unit 14 may determineto use one of the sides including the larger number of frames betweenthe predetermined threshold and a defocus value closest to the end ofthe Inf side or a defocus value closest to the end of the Macro side.

Further, when selecting a frame on the Inf side or the Macro side, themain processing unit 14 may select a frame farthest from the referenceframe or may select a frame closest to the reference frame. Further, themain processing unit 14 may determine the lens position on the basis ofan average of the defocus values of the frames on the Inf side or theMacro side.

On the contrary, if, as a result of the determination performed in StepS123, the number of bins in which the number of unit elements is thepredetermined threshold or more is less than two (Step S123, No), themain processing unit 14 determines the lens position on the basis of thedefocus value of the reference frame and causes PDAF or CDAF to beexecuted (Step S125). The determination of the lens position of theimaging optical system 11A is performed by the determination unit 112.

By executing the above-described series of operation, even if subjectsexist on both the infinity side (Inf side) and the macro side (Macroside) in the subject detection region 130, the main processing unit 14can determine the lens position of the imaging optical system 11A sothat one of the subjects can be in focus.

Further, in this method 3, even if the defocus value of the referenceframe does not satisfy the phase difference reliability, it is possibleto execute the above-described series of processing because thecalculated defocus values of the subject detection region 130 and thenine divided regions are converted into a histogram.

(Method 4)

A method 4 regarding the lens position determination processing is amethod of converting the calculated defocus values of the subjectdetection region 130 and the nine divided regions into a histogram anddetermining that a subject exists on the macro side or infinity side ina case where the defocus values converted into the histogram satisfy apredetermined condition, thereby determining the lens position of theimaging optical system 11A on the macro side or infinity side.

In this method 4, as the predetermined condition, a condition that, in acase where unit elements included in a histogram are adjacent, thenumber of unit elements is counted and a percentage of the sum of unitelements in a group (bin) having the largest number of unit elements andunit elements in a group having the second largest number of unitelements is a predetermined value or more, relative to the number of allunit elements, is used. If this condition is satisfied, it is determinedthat a subject exists on the macro side or infinity side, and the lensposition of the imaging optical system 11A is determined on the macroside or infinity side.

In the example of FIG. 17, the number of adjacent unit elements is 3, 3,1, 2, and 1 from the left side. Therefore, the sum of unit elements inthe group (bin) having the largest number of unit elements and unitelements in the group having the second largest number of unit elementsis 6.

When the threshold is 50%, the percentage of the sum of unit elementsrelative to all the unit elements is 60%, i.e., exceeds the threshold,and therefore it is determined that a subject exists on the macro sideor infinity side, and the lens position of the imaging optical system11A is determined to be on the macro side or infinity side.

FIG. 19 is a flowchart showing the lens position determinationprocessing performed by the main processing unit 14 by using the method4. Hereinafter, the lens position determination processing performed bythe main processing unit 14 by using the method 4 will be described withreference to FIG. 19.

The main processing unit 14 first calculates defocus values of thereference frame and divided frames in a state in which the lens positionof the imaging optical system 11A is at a predetermined position andconverts the defocus values into a histogram (Step S131). Thecalculation of defocus values and the conversion thereof into ahistogram in Step S131 are performed by the calculation unit 111.

In a way similar to the methods 1 to 3, the main processing unit 14 maybe configured not to use, in the subsequent lens position determinationprocessing, a frame whose phase difference reliability does not satisfya predetermined reference when the defocus values of the reference frameand divided frames are calculated.

When the defocus values of the reference frame and divided frames arecalculated and are converted into a histogram in Step S131, then themain processing unit 14 acquires the number of bins including adjacentunit elements in the histogram (Step S132). The acquisition processingin Step S132 is performed by, for example, the determination unit 112.

When the number of bins including adjacent unit elements in thehistogram is acquired in Step S132, then the main processing unit 14determines whether or not a percentage of the sum of unit elements in abin having the largest number of unit elements and unit elements in abin having the second largest number of unit elements relative to thenumber of all the unit elements is a predetermined value or more (StepS133). The determination processing in Step S133 is performed by, forexample, the determination unit 112.

If, as a result of the determination in Step S133, the percentage of thesum of the number of unit elements in the bin having the largest numberof unit elements and the number of unit elements in the bin having thesecond largest number of unit elements relative to the number of all theunit elements is the predetermined value or more (Step S133, Yes), themain processing unit 14 determines the lens position on the basis ofdefocus values on the Inf side or the Macro side and causes PDAF or CDAFto be executed (Step S134). The determination of the lens position ofthe imaging optical system 11A is performed by the determination unit112.

The main processing unit 14 may determine which of PDAF or CDAF to beexecuted, on the basis of a previous setting or on the basis ofdesignation made by a user.

Further, when causing PDAF or CDAF to be executed, the main processingunit 14 may determine which of the defocus values on the Inf side or thedefocus values on the Macro side to use, on the basis of a previoussetting or on the basis of designation made by a user.

Further, regarding determination on which of the defocus values on theInf side or the defocus values on the Macro side to use when causingPDAF or CDAF to be executed, the main processing unit 14 may determineto use one of the sides having the larger number of frames between thepredetermined threshold and a defocus value closest to the end of theInf side or the end of the Macro side.

Further, when selecting a frame on the Inf side or the Macro side, themain processing unit 14 may select a frame farthest from the referenceframe or may select a frame closest to the reference frame. Further, themain processing unit 14 may determine the lens position on the basis ofan average of the defocus values of the frames on the Inf side or theMacro side.

On the contrary, if, as a result of the determination in Step S133, thepercentage of the sum of the number of unit elements in the bin havingthe largest number of unit elements and the number of unit elements inthe bin having the second largest number of unit elements relative tothe number of all the unit elements is less than the predetermined value(Step S133, No), the main processing unit 14 determines the lensposition on the basis of the defocus value of the reference frame andcauses PDAF or CDAF to be executed (Step S135). The determination of thelens position of the imaging optical system 11A is performed by thedetermination unit 112.

By executing the above-described series of operation, even if subjectsexist on both the infinity side (Inf side) and the macro side (Macroside) in the subject detection region 130, the main processing unit 14can determine the lens position of the imaging optical system 11A sothat one of the subjects can be in focus.

Further, in this method 4, in a way similar to the method 3, even if thedefocus value of the reference frame does not satisfy the phasedifference reliability, it is possible to execute the above-describedseries of processing because the calculated defocus values of thesubject detection region 130 and the nine divided regions are convertedinto a histogram.

(Method 5)

A method 5 regarding the lens position determination processing is amethod of converting the calculated defocus values of the subjectdetection region 130 and the nine divided regions into a histogram anddetermining that a subject exists on the macro side or infinity side ifthe defocus values converted into the histogram satisfy a predeterminedcondition, thereby determining the lens position of the imaging opticalsystem 11A to be on the macro side or infinity side.

FIG. 20 is an explanatory view illustrating an outline of the method 5regarding the lens position determination processing. FIG. 20illustrates an example in which the calculated defocus values of thesubject detection region 130 and the nine divided regions are arrangedin a histogram and the histogram is smoothed.

In this method 5, as the predetermined condition, a condition that thehistogram of the defocus values is smoothed and a plurality of peaksexceeding a predetermined threshold exist in the smoothed histogram isused. If this condition is satisfied, it is determined that a subjectexists on the macro side or infinity side, and the lens position of theimaging optical system 11A is determined to be on the macro side orinfinity side.

FIG. 21 is a flowchart showing the lens position determinationprocessing performed by the main processing unit 14 by using the method5. Hereinafter, the lens position determination processing performed bythe main processing unit 14 by using the method 5 will be described withreference to FIG. 21.

The main processing unit 14 first calculates defocus values of thereference frame and the divided frames in a state in which the lensposition of the imaging optical system 11A is at a predeterminedposition and converts the defocus values into a histogram (Step S141).The calculation of defocus values and the conversion thereof into ahistogram in Step S141 are performed by the calculation unit 111.

In a way similar to the methods 1 to 4, the main processing unit 14 maybe configured not to use, in the subsequent lens position determinationprocessing, a frame whose phase difference reliability does not satisfya predetermined reference when the defocus values of the reference frameand the divided frames are calculated.

When the defocus values of the reference frame and the divided framesare calculated and are converted into a histogram in Step S141, then themain processing unit 14 smoothes the generated histogram and detects apeak exceeding a predetermined threshold (Step S142). The smoothingprocessing and the peak detection processing in Step S142 are performedby the calculation unit 111.

When the histogram is smoothed in Step S142, then the main processingunit 14 determines whether or not a plurality of peaks exceeding thepredetermined threshold exist in the smoothed histogram (Step S143). Thedetermination processing in Step S143 is performed by, for example, thedetermination unit 112.

If, as a result of the determination in Step S143, a plurality of peakexceeding the predetermined threshold exist in the smoothed histogram(Step S143, Yes), the main processing unit 14 determines the lensposition on the basis of defocus values on the Inf side or the Macroside and causes PDAF or CDAF to be executed (Step S144). Thedetermination of the lens position of the imaging optical system 11A isperformed by the determination unit 112.

The main processing unit 14 may determine which of PDAF or CDAF toexecute, on the basis of a previous setting or on the basis ofdesignation made by a user.

Further, when executing PDAF or CDAF is executed, the main processingunit 14 may determine which of the defocus values on the Inf side or onthe Macro side to use, on the basis of a previous setting or on thebasis of designation made by a user.

Further, regarding determination on which of the defocus values on theInf side or on the Macro side to use when causing PDAF or CDAF to beexecuted, the main processing unit 14 may determine to use one of thesides having the larger number of frames between the predeterminedthreshold and a defocus value closest to the end of the Inf side or theend of the Macro side.

Further, when selecting a frame on the Inf side or the Macro side, themain processing unit 14 may select a frame farthest from the referenceframe or may select a frame closest to the reference frame. Further, themain processing unit 14 may determine the lens position on the basis ofan average of the defocus values of frames on the Inf side or the Macroside.

On the contrary, if, as a result of the determination in Step S143, aplurality of peak exceeding the predetermined threshold do not exist inthe smoothed histogram (Step S143, No), the main processing unit 14determines the lens position on the basis of the defocus value of thereference frame and causes PDAF or CDAF to be executed (Step S145). Thedetermination of the lens position of the imaging optical system 11A isperformed by the determination unit 112.

By executing the above-described series of operation, even if subjectsexist on both the infinity side (Inf side) and the macro side (Macroside) in the subject detection region 130, the main processing unit 14can determine the lens position of the imaging optical system 11A sothat one of the subjects can be in focus.

Further, in this method 5, in a way similar to the methods 3 and 4, evenif the defocus value of the reference frame does not satisfy the phasedifference reliability, it is possible to execute the above-describedseries of processing because the calculated defocus values of thesubject detection region 130 and the nine divided regions are convertedinto a histogram.

Further, in this method 5, because the histogram is smoothed, it ispossible to determine the lens position to be on the infinity side ormacro side even in a case where unit elements of the histogram are notadjacent.

(Method 6)

A method 5 regarding the lens position determination processing is amethod of converting the calculated defocus values of the subjectdetection region 130 and the nine divided regions into a histogram anddetermining that a subject exists on the macro side or infinity side ifthe defocus values converted into the histogram satisfy a predeterminedcondition, thereby determining the lens position of the imaging opticalsystem 11A to be on the macro side or infinity side.

FIG. 22 is an explanatory view illustrating an outline of the method 6regarding the lens position determination processing. FIG. 22illustrates an example in which the calculated defocus values of thesubject detection region 130 and the nine divided regions are added in atime direction, are then arranged in a histogram, and the histogram issmoothed. In FIG. 22, a horizontal axis shows a target position of thelens of the imaging optical system 11A obtained on the basis of thedefocus values added in the time direction.

In this method 6, as the predetermined condition, a condition that thedefocus values are added in the time direction, are then converted intoa histogram and smoothed, and a plurality of peaks exceeding apredetermined threshold exist in the smoothed histogram is used. If thiscondition is satisfied, it is determined that a subject exists on themacro side or infinity side, and the lens position of the imagingoptical system 11A is determined to be on the macro side or infinityside.

FIG. 23 is a flowchart showing the lens position determinationprocessing performed by the main processing unit 14 by using the method6. Hereinafter, the lens position determination processing performed bythe main processing unit 14 by using the method 6 will be described withreference to FIG. 23.

The main processing unit 14 first calculates defocus values of thereference frame and the divided frames in a state in which the lensposition of the imaging optical system 11A is at a predeterminedposition, adds the defocus values in the time direction, and thenconverts the defocus values into a histogram (Step S151). Thecalculation of defocus values, the addition of the defocus values in thetime direction, and the conversion of the defocus values into ahistogram in Step S151 are performed by the calculation unit 111.

In a way similar to the methods 1 to 5, the main processing unit 14 maybe configured not to use, in the subsequent lens position determinationprocessing, a frame whose phase difference reliability does not satisfya predetermined reference when the defocus values of the reference frameand the divided frames are calculated.

When the defocus values of the reference frame and the divided framesare calculated, and the defocus values are added in the time directionand converted into a histogram in Step S151, then the main processingunit 14 smoothes the generated histogram and detects a peak exceeding apredetermined threshold (Step S152). The smoothing processing and thepeak detection processing in Step S152 are performed by the calculationunit 111.

When the histogram is smoothed in Step S142, then the main processingunit 14 determines whether or not a plurality of peaks exceeding thepredetermined threshold exist in the smoothed histogram (Step S143). Thedetermination processing in Step S143 is performed by, for example, thedetermination unit 112.

If, as a result of the determination in Step S153, a plurality of peakexceeding the predetermined threshold exist in the smoothed histogram(Step S153, Yes), the main processing unit 14 determines the lensposition on the basis of defocus values on the Inf side or the Macroside and causes PDAF or CDAF to be executed (Step S154). Thedetermination of the lens position of the imaging optical system 11A isperformed by the determination unit 112.

The main processing unit 14 may determine which of PDAF or CDAF to beexecuted, on the basis of a previous setting or on the basis ofdesignation made by a user.

Further, when causing PDAF or CDAF to be executed, the main processingunit 14 may determine which of the defocus values on the Inf side or theMacro side to use, on the basis of a previous setting or on the basis ofdesignation made by a user.

Further, regarding determination on which of defocus values on the Infside or the Macro side to use when causing PDAF or CDAF to be executed,the main processing unit 14 may determine to use one of the sides havingthe larger number of frames between the predetermined threshold and adefocus value closest to the end of the Inf side or the end of the Macroside.

Further, when selecting a frame on the Inf side or the Macro side, themain processing unit 14 may select a frame farthest from the referenceframe or may select a frame closest to the reference frame. Further, themain processing unit 14 may determine the lens position on the basis ofan average of the defocus values of frames on the Inf side or the Macroside.

On the contrary, if, as a result of the determination in Step S153, aplurality of peak exceeding the predetermined threshold do not exist inthe smoothed histogram (Step S153, No), the main processing unit 14determines the lens position on the basis of the defocus value of thereference frame and causes PDAF or CDAF to be executed (Step S155). Thedetermination of the lens position of the imaging optical system 11A isperformed by the determination unit 112.

By executing the above-described series of operation, even if subjectsexist on both the infinity side (Inf side) and the macro side (Macroside) in the subject detection region 130, the main processing unit 14can determine the lens position of the imaging optical system 11A sothat one of the subjects can be in focus.

Further, in this method 6, in a way similar to the methods 3 to 5, evenif the defocus value of the reference frame does not satisfy the phasedifference reliability, it is possible to execute the above-describedseries of processing because the calculated defocus values of thesubject detection region 130 and the nine divided regions are convertedinto a histogram.

Further, in this method 6, in a way similar to the method 5, because thehistogram is smoothed, it is possible to determine the lens position tobe on the infinity side or macro side even in a case where unit elementsof the histogram are not adjacent.

Further, in this method 6, the total number of unit elements in ahistogram is larger than the methods 3 to 5, and therefore it ispossible to improve determination accuracy of the lens position.

Note that the focus position in the present disclosure may correspond toan image shift amount including a phase difference or defocus value. Thedefocus value is a value indicating a distance and direction from acurrent lens position to a focusing position, and therefore obtaining adefocus value corresponds to an example of calculating a focus positionin the present disclosure. By analyzing a focus position in each region,the main processing unit 14 can calculate, on the basis of the focuspositions, a moving amount of the lens of the imaging optical system 11Afor causing a subject to be in focus.

(Application Example)

The above-described camera module can be used for, for example, variouselectronic devices that sense light such as visible light, infraredlight, ultraviolet light, or X-rays as described below.

Electronic devices that take images used for viewing, such as a digitalcamera and a portable appliance with a camera function.

-   -   Electronic devices used for traffic, such as an in-vehicle        sensor that takes images of the front and the back of a car,        surroundings, the inside of the car, and the like, a monitoring        camera that monitors travelling vehicles and roads, and a        distance sensor that measures distances between vehicles and the        like, which are used for safe driving (e.g., automatic stop),        recognition of the condition of a driver, and the like.    -   Electronic devices used for home electrical appliances, such as        a TV, a refrigerator, and an air conditioner, to takes images of        a gesture of a user and operate appliances in accordance with        the gesture.    -   Electronic devices used for medical care and health care, such        as an endoscope and a device that performs angiography by        reception of infrared light.    -   Electronic devices used for security, such as a monitoring        camera for crime prevention and a camera for personal        authentication.    -   Electronic devices used for beauty care, such as skin        measurement equipment that takes images of the skin and a        microscope that takes images of the scalp.    -   Electronic devices used for sports, such as an action camera and        a wearable camera for sports and the like.    -   Electronic devices used for agriculture, such as a camera for        monitoring the condition of the field and crops.

2. Conclusion

As described above, according to an embodiment of the presentdisclosure, it is possible to provide a camera module capable ofdetermining the lens position of the imaging optical system 11A so that,even when subjects exist on both the infinity side (Inf side) and themacro side (Macro side) in the subject detection region 130, one of thesubjects can be in focus.

For example, the main processing unit 14 arranges calculated defocusvalues of the subject detection region 130 and the nine divided regions,and determines that a subject exists on the macro side or infinity sideif the number of regions between a defocus value on a macro side or aninfinity side to a predetermined threshold is a predetermined value ormore, thereby determining the lens position of the imaging opticalsystem 11A.

Further, for example, the main processing unit 14 arranges calculateddefocus values of the subject detection region 130 and the nine dividedregions, determines whether or not the number of regions that is out ofranges from a defocus value of the reference frame to predeterminedthresholds in the infinity-side (Inf-side) and macro-side (Macro-side)directions is a predetermined value or more, and determines that asubject exists on the macro side or infinity side if the number ofregions that is out of the ranges between the predetermined thresholdsis the predetermined value or more, thereby determining the lensposition of the imaging optical system 11A to be on the macro side orinfinity side.

Further, for example, in the method 3 regarding the lens positiondetermination processing, the main processing unit 14 convertscalculated defocus values of the subject detection region 130 and thenine divided regions into a histogram and determines that a subjectexists on the macro side or infinity side if the defocus valuesconverted into the histogram satisfy a predetermined condition, therebydetermining the lens position of the imaging optical system 11A to be onthe macro side or infinity side.

The predetermined condition may be, for example, a condition that, in acase where unit elements included in a histogram are adjacent, thenumber of the adjacent unit elements is counted and the number of groupsin which the number of unit elements is a threshold or more is two ormore, or may be a condition that, in a case where unit elements includedin a histogram are adjacent, the number of the adjacent unit elements iscounted and a percentage of the sum of unit elements in a group havingthe largest number of unit elements and unit elements in a group havingthe second largest number of unit elements relative to the number of allunit elements is a predetermined value or more.

Further, the predetermined condition may be a condition that a histogramof defocus values is smoothed and a plurality of peaks exceeding apredetermined threshold exist in the smoothed histogram, or may be acondition that defocus values are added in the time direction, thenconverted into a histogram, and smoothed, and a plurality of peaksexceeding a predetermined threshold exist in the smoothed histogram.

Processing steps in processes of the present specification may notnecessarily be executed in a time series manner in the order describedin the flowcharts or sequence diagrams. The processing steps in theprocesses may also be executed in, for example, a different order fromthe order described in the flowcharts or sequence diagrams, or may beexecuted in parallel.

Furthermore, a computer program for causing a processor (e.g., a CPU, aDSP, etc.) provided in a device of the present specification to functionas the device (i.e., a computer program for causing the processor toexecute operations of structural elements of the above-described device)can also be created. In addition, a recording medium in which thecomputer program is recorded may be provided. Moreover, a device thatincludes a memory storing the computer program and one or moreprocessors that can execute the computer program (e.g., a finishedproduct or a module for a finished product (a component, a processingcircuit, a chip, or the like) may also be provided. In addition, amethod including operations of one or more structural elements of thedevice is also included in the technology of the present disclosure.

The preferred embodiment(s) of the present disclosure has/have beendescribed above with reference to the accompanying drawings, whilst thepresent disclosure is not limited to the above examples. A personskilled in the art may find various alterations and modifications withinthe scope of the appended claims, and it should be understood that theywill naturally come under the technical scope of the present disclosure.

Further, the effects described in this specification are merelyillustrative or exemplified effects, and are not limitative. That is,with or in the place of the above effects, the technology according tothe present disclosure may achieve other effects that are clear to thoseskilled in the art from the description of this specification.

Additionally, the present technology may also be configured as below.

(1)

A control device including:

a calculation unit configured to calculate, on a basis of a result ofcapturing a subject image passed through a focus lens by using animaging element including a plurality of phase difference detectionregions, a focus position of each of the phase difference detectionregions; and

a determination unit configured to determine a position of the focuslens on a basis of an average value of the focus positions of the phasedifference detection regions calculated by the calculation unit andfalling within a predetermined range from the focus position on aninfinity side or macro side.

(2)

The control device according to (1),

in which, if a number of the phase difference detection regions havingthe focus positions falling within the predetermined range is apredetermined threshold or more, the determination unit determines theposition of the focus lens on a basis of the average value of the focuspositions of the phase difference detection regions calculated by thecalculation unit.

(3)

The control device according to (1) or (2),

in which the phase difference detection region includes a first regionand a plurality of second regions having at least a part overlappingwith the first region.

(4)

A control device including:

a calculation unit configured to calculate, on a basis of a result ofcapturing a subject image passed through a focus lens by using animaging element including a plurality of phase difference detectionregions, a focus position of each of the phase difference detectionregions; and

a determination unit configured to determine a position of the focuslens on a basis of the focus position on an infinity side or macro sideif a number of the phase difference detection regions whose focuspositions are apart from the focus position of the phase differencedetection region serving as a reference by a predetermined range ormore, is a predetermined value or more.

(5)

A control device including:

a calculation unit configured to calculate, on a basis of a result ofcapturing a subject image passed through a focus lens by using animaging element including a plurality of phase difference detectionregions, a focus position of each of the phase difference detectionregions and convert the focus positions into a histogram; and

a determination unit configured to determine a position of the focuslens on a basis of the focus position on an infinity side or macro sidein a case where each of the focus positions of the phase differencedetection regions converted into the histogram satisfies a firstpredetermined condition.

(6)

The control device according to (5),

in which the first predetermined condition is a condition that aplurality of groups in which a number of adjacent unit elements in thehistogram is a predetermined value or more exists.

(7)

The control device according to (5),

in which the first predetermined condition is a condition that aplurality of groups in which a number of adjacent unit elements in thehistogram is a predetermined value or more exists and a number of unitelements in the groups satisfies a second predetermined condition.

(8)

The control device according to (7),

in which the second predetermined condition is a condition that apercentage of a sum of a number of unit elements in a group having alargest number of unit elements and a number of unit elements in a grouphaving a second largest number of unit elements relative to a number ofall unit elements is a predetermined value or more.

(9)

The control device according to (5),

in which the calculation unit smoothes the focus positions of therespective phase difference detection regions converted into thehistogram, and

the first predetermined condition is a condition that a plurality ofpeaks exceeding a predetermined threshold exist in the smoothedhistogram.

(10)

The control device according to (5),

in which the calculation unit adds predetermined time to the focuspositions converted into the histogram and smoothes the focus positions,and

the first predetermined condition is a condition that a plurality ofpeaks exceeding a predetermined threshold exist in the smoothedhistogram.

(11)

A control method including:

calculating, on a basis of a result of capturing a subject image passedthrough a focus lens by using an imaging element including a pluralityof phase difference detection regions, a focus position of each of thephase difference detection regions; and

determining a position of the focus lens on a basis of an average valueof the calculated focus positions of the phase difference detectionregions falling within a predetermined range from the focus position onan infinity side or macro side.

(12)

A control method including:

calculating, on a basis of a result of capturing a subject image passedthrough a focus lens by using an imaging element including a pluralityof phase difference detection regions, a focus position of each of thephase difference detection regions; and

determining a position of the focus lens on a basis of the focusposition on an infinity side or macro side if a number of the phasedifference detection regions whose focus positions are apart from thefocus position in the phase difference detection region serving as areference by a predetermined range or more, is a predetermined value ormore.

(13)

A control method including:

calculating, on a basis of a result of capturing a subject image passedthrough a focus lens by using an imaging element including a pluralityof phase difference detection regions, a focus position of each of thephase difference detection regions and converting the focus positionsinto a histogram; and

determining a position of the focus lens on a basis of the focusposition on an infinity side or macro side in a case where each of thefocus positions of the phase difference detection regions converted intothe histogram satisfies a first predetermined condition.

(14)

A computer program for causing a computer execute

calculating, on a basis of a result of capturing a subject image passedthrough a focus lens by using an imaging element including a pluralityof phase difference detection regions, a focus position of each of thephase difference detection regions, and

determining a position of the focus lens on a basis of an average valueof the calculated focus positions of the phase difference detectionregions falling within a predetermined range from the focus position onan infinity side or macro side.

(15)

A computer program for causing a computer execute

calculating, on a basis of a result of capturing a subject image passedthrough a focus lens by using an imaging element including a pluralityof phase difference detection regions, a focus position of each of thephase difference detection regions, and

determining a position of the focus lens on a basis of the focusposition on an infinity side or macro side if a number of the phasedifference detection regions whose focus positions are apart from thefocus position in the phase difference detection region serving as areference by a predetermined range or more, is a predetermined value ormore.

(16)

A computer program for causing a computer execute

calculating, on a basis of a result of capturing a subject image passedthrough a focus lens by using an imaging element including a pluralityof phase difference detection regions, a focus position of each of thephase difference detection regions and converting the focus positionsinto a histogram, and

determining a position of the focus lens on a basis of the focusposition on an infinity side or macro side in a case where each of thefocus positions of the phase difference detection regions converted intothe histogram satisfies a first predetermined condition.

(17)

An electronic device including:

an imaging optical system configured to collect light;

an imaging element configured to receive light from the imaging opticalsystem and capture an image; and

a signal processing unit configured to process a signal output by theimaging element,

in which the signal processing unit includes

-   -   a calculation unit configured to calculate, on a basis of a        result of capturing a subject image passed through a focus lens        by using the imaging element including a plurality of phase        difference detection regions, a focus position of each of the        phase difference detection regions, and    -   a determination unit configured to determine a position of the        focus lens on a basis of an average value of the focus positions        of the phase difference detection regions calculated by the        calculation unit and falling within a predetermined range from        the focus position on an infinity side or macro side.

(18)

An electronic device including:

an imaging optical system configured to collect light;

an imaging element configured to receive light from the imaging opticalsystem and capture an image; and

a signal processing unit configured to process a signal output by theimaging element,

in which the signal processing unit includes

-   -   a calculation unit configured to calculate, on a basis of a        result of capturing a subject image passed through a focus lens        by using the imaging element including a plurality of phase        difference detection regions, a focus position of each of the        phase difference detection regions, and    -   a determination unit configured to determine a position of the        focus lens on a basis of the focus position on an infinity side        or macro side if a number of the phase difference detection        regions whose focus positions are apart from the focus position        of the phase difference detection region serving as a reference        by a predetermined range or more, is a predetermined value or        more.

(19)

An electronic device including:

an imaging optical system configured to collect light;

an imaging element configured to receive light from the imaging opticalsystem s

a signal processing unit configured to process a signal output by theimaging element,

in which the signal processing unit includes

-   -   a calculation unit configured to calculate, on a basis of a        result of capturing a subject image passed through a focus lens        by using the imaging element including a plurality of phase        difference detection regions, a focus position of each of the        phase difference detection regions and convert the focus        positions into a histogram, and    -   a determination unit configured to determine a position of the        focus lens on a basis of the focus position on an infinity side        or macro side in a case where each of the focus positions of the        phase difference detection regions converted into the histogram        satisfies a first predetermined condition.

REFERENCE SIGNS LIST

-   11 lens barrel-   11A imaging optical system-   12 optical filter-   13 image sensor-   14 main processing unit-   15 illumination control unit-   16 sensor drive unit-   17 phase detection AF processing unit-   18 image processing unit-   19 focus drive unit-   20 display unit-   21 operation unit-   22 flash memory-   31 CPU-   32 memory-   33 ADC-   34 DAC-   35 communication I/F-   50 light receiving surface-   51 pixel block-   52 normal pixel-   53 detection pixel-   53L left light-shielding pixel-   53R right light-shielding pixel-   61 PD-   62 CL-   63 color filter-   64 on-chip lens-   66 light-shielding film

1. A control device comprising: a calculation unit configured tocalculate, on a basis of a result of capturing a subject image passedthrough a focus lens by using an imaging element including a pluralityof phase difference detection regions, a focus position of each of thephase difference detection regions; and a determination unit configuredto determine a position of the focus lens on a basis of an average valueof the focus positions of the phase difference detection regionscalculated by the calculation unit and falling within a predeterminedrange from the focus position on an infinity side or macro side.
 2. Thecontrol device according to claim 1, wherein, if a number of the phasedifference detection regions having the focus positions falling withinthe predetermined range is a predetermined threshold or more, thedetermination unit determines the position of the focus lens on a basisof the average value of the focus positions of the phase differencedetection regions calculated by the calculation unit.
 3. The controldevice according to claim 1, wherein the phase difference detectionregion includes a first region and a plurality of second regions havingat least a part overlapping with the first region.
 4. A control devicecomprising: a calculation unit configured to calculate, on a basis of aresult of capturing a subject image passed through a focus lens by usingan imaging element including a plurality of phase difference detectionregions, a focus position of each of the phase difference detectionregions; and a determination unit configured to determine a position ofthe focus lens on a basis of the focus position on an infinity side ormacro side if a number of the phase difference detection regions whosefocus positions are apart from the focus position of the phasedifference detection region serving as a reference by a predeterminedrange or more, is a predetermined value or more.
 5. A control devicecomprising: a calculation unit configured to calculate, on a basis of aresult of capturing a subject image passed through a focus lens by usingan imaging element including a plurality of phase difference detectionregions, a focus position of each of the phase difference detectionregions and convert the focus positions into a histogram; and adetermination unit configured to determine a position of the focus lenson a basis of the focus position on an infinity side or macro side in acase where each of the focus positions of the phase difference detectionregions converted into the histogram satisfies a first predeterminedcondition.
 6. The control device according to claim 5, wherein the firstpredetermined condition is a condition that a plurality of groups inwhich a number of adjacent unit elements in the histogram is apredetermined value or more exists.
 7. The control device according toclaim 5, wherein the first predetermined condition is a condition that aplurality of groups in which a number of adjacent unit elements in thehistogram is a predetermined value or more exists and a number of unitelements in the groups satisfies a second predetermined condition. 8.The control device according to claim 7, wherein the secondpredetermined condition is a condition that a percentage of a sum of anumber of unit elements in a group having a largest number of unitelements and a number of unit elements in a group having a secondlargest number of unit elements relative to a number of all unitelements is a predetermined value or more.
 9. The control deviceaccording to claim 5, wherein the calculation unit smoothes the focuspositions of the respective phase difference detection regions convertedinto the histogram, and the first predetermined condition is a conditionthat a plurality of peaks exceeding a predetermined threshold exist inthe smoothed histogram.
 10. The control device according to claim 5,wherein the calculation unit adds predetermined time to the focuspositions converted into the histogram and smoothes the focus positions,and the first predetermined condition is a condition that a plurality ofpeaks exceeding a predetermined threshold exist in the smoothedhistogram.
 11. A control method comprising: calculating, on a basis of aresult of capturing a subject image passed through a focus lens by usingan imaging element including a plurality of phase difference detectionregions, a focus position of each of the phase difference detectionregions; and determining a position of the focus lens on a basis of anaverage value of the calculated focus positions of the phase differencedetection regions falling within a predetermined range from the focusposition on an infinity side or macro side.
 12. A control methodcomprising: calculating, on a basis of a result of capturing a subjectimage passed through a focus lens by using an imaging element includinga plurality of phase difference detection regions, a focus position ofeach of the phase difference detection regions; and determining aposition of the focus lens on a basis of the focus position on aninfinity side or macro side if a number of the phase differencedetection regions whose focus positions are apart from the focusposition in the phase difference detection region serving as a referenceby a predetermined range or more, is a predetermined value or more. 13.A control method comprising: calculating, on a basis of a result ofcapturing a subject image passed through a focus lens by using animaging element including a plurality of phase difference detectionregions, a focus position of each of the phase difference detectionregions and converting the focus positions into a histogram; anddetermining a position of the focus lens on a basis of the focusposition on an infinity side or macro side in a case where each of thefocus positions of the phase difference detection regions converted intothe histogram satisfies a first predetermined condition.
 14. A computerprogram for causing a computer execute calculating, on a basis of aresult of capturing a subject image passed through a focus lens by usingan imaging element including a plurality of phase difference detectionregions, a focus position of each of the phase difference detectionregions, and determining a position of the focus lens on a basis of anaverage value of the calculated focus positions of the phase differencedetection regions falling within a predetermined range from the focusposition on an infinity side or macro side.
 15. A computer program forcausing a computer execute calculating, on a basis of a result ofcapturing a subject image passed through a focus lens by using animaging element including a plurality of phase difference detectionregions, a focus position of each of the phase difference detectionregions, and determining a position of the focus lens on a basis of thefocus position on an infinity side or macro side if a number of thephase difference detection regions whose focus positions are apart fromthe focus position in the phase difference detection region serving as areference by a predetermined range or more, is a predetermined value ormore.
 16. A computer program for causing a computer execute calculating,on a basis of a result of capturing a subject image passed through afocus lens by using an imaging element including a plurality of phasedifference detection regions, a focus position of each of the phasedifference detection regions and converting the focus positions into ahistogram, and determining a position of the focus lens on a basis ofthe focus position on an infinity side or macro side in a case whereeach of the focus positions of the phase difference detection regionsconverted into the histogram satisfies a first predetermined condition.17. An electronic device comprising: an imaging optical systemconfigured to collect light; an imaging element configured to receivelight from the imaging optical system and capture an image; and a signalprocessing unit configured to process a signal output by the imagingelement, wherein the signal processing unit includes a calculation unitconfigured to calculate, on a basis of a result of capturing a subjectimage passed through a focus lens by using the imaging element includinga plurality of phase difference detection regions, a focus position ofeach of the phase difference detection regions, and a determination unitconfigured to determine a position of the focus lens on a basis of anaverage value of the focus positions of the phase difference detectionregions calculated by the calculation unit and falling within apredetermined range from the focus position on an infinity side or macroside.
 18. An electronic device comprising: an imaging optical systemconfigured to collect light; an imaging element configured to receivelight from the imaging optical system and capture an image; and a signalprocessing unit configured to process a signal output by the imagingelement, wherein the signal processing unit includes a calculation unitconfigured to calculate, on a basis of a result of capturing a subjectimage passed through a focus lens by using the imaging element includinga plurality of phase difference detection regions, a focus position ofeach of the phase difference detection regions, and a determination unitconfigured to determine a position of the focus lens on a basis of thefocus position on an infinity side or macro side if a number of thephase difference detection regions whose focus positions are apart fromthe focus position of the phase difference detection region serving as areference by a predetermined range or more, is a predetermined value ormore.
 19. An electronic device comprising: an imaging optical systemconfigured to collect light; an imaging element configured to receivelight from the imaging optical system and capture an image; and a signalprocessing unit configured to process a signal output by the imagingelement, wherein the signal processing unit includes a calculation unitconfigured to calculate, on a basis of a result of capturing a subjectimage passed through a focus lens by using the imaging element includinga plurality of phase difference detection regions, a focus position ofeach of the phase difference detection regions and convert the focuspositions into a histogram, and a determination unit configured todetermine a position of the focus lens on a basis of the focus positionon an infinity side or macro side in a case where each of the focuspositions of the phase difference detection regions converted into thehistogram satisfies a first predetermined condition.